Need help with inbound action script - Email to Close case if accept in subject

[Hari7]

I have a requirement to update the HR Case based on the reply received and change its status to Closed or WIP.

When the case is set to Awaiting Acceptance, we are sending email notification with 2 options, accept and reject.

When the user selects Accept, email will be sent with the subject "accept" and if they click on reject, email subject will be "reject".

Based on the options, case has to be set to "Closed completed" for Accept and WIP for Reject.

Please help with how to get this done on the inbound action.

I created Flow Designer for this logic but it didnt work. 

Flow Trigger

Flow Execution:

[Hari7]

I went with the traditional scripting method of the inbound action and it works well but dont have luck with the flow designer inbound action. 

[Simran321]

@Hari7 - I need to setup email with Accept and Reject button. Can you share the mail script for accept